Moonwalker PCB: All socketed chips removed. What to do?

[ifkz]

Moonwalker PCB: All socketed chips removed. What to do?

I know this PCB has gotten more respect after the entertainer's death, going to unaffordable levels for those wishing to play the game on real hardware. I remember playing the game in my arcade days and I liked it.

Back to the point, I was given a nice PCB recently, but it has all of the socketed chips removed, including even the PALs and amp heatsink. It's a sad fate for a pretty rare game. What would you do?

1. Wait for a junk, but complete system18 game to come up?
2. Wait for 17 27020's to come my way? Thanks to members here, I think I can get a rom set together that runs on a regular 68000 CPU.
3. Hang the PCB on the wall as art?

 

[EagleTG]

#2. Roms are available. http://www.pinballzone.com/tech/fd1094/index.htm

Combine those with MAME roms (or get dumps from others here).

 

[Solder]

The problem is going to be replacing the PALs - these don't appear to have been dumped or reverse engineered, and without them the board will never work. The only option is to obtain PALs from another System 18 main board (preferably one that is beyond repair).

Of course, ifkz's board may also be in need of repair, only way to find out is to pop all the chips back in and fire it up.

 

[ifkz]

Yes, I can understand removing EPROMS to reprogram for another game, but the PALS, TMS, amp heatsink, and transistor screws & nuts? That is beyond the call. Poor game. Here's hoping I can get a trashed out but complete system18 game, and some 27020's to use with my unencrypted romset.

After going through my other trashed boards, I found PAL from Outrun that had the same part number. I assume these are just ICs and are interchangeable. I also found a 10 Mhz 68000 CPU from the Outrun. A start for this rare game.

 

[Solder]

The parts were probably removed as the board most likely had a fault. Not sure what you can do really - the other parts that you mentioned aren't hard to replace, it's the PALs that are the sticking point.

 

[EagleTG]

If you consider selling the bare board, let me know. Mine has a weird issue I have yet to track down, I know it's either socket or trace related... Some sort of connection thing.

Thanks.

 

[ifkz]

...And if you decide to let your troublesome board go, let me know.

Oh, I forgot to mention, they also pulled off every dip switch from the ROM board too. I'd love to find the box they used back when it was stripped.

 

[EagleTG]

...And if you decide to let your troublesome board go, let me know.

Ahh, it's a stand-off you want?! I'll draw a line in the sand, and we'll Moonwalk 10 paces. First though, let me find my sequin glove and Members Only jacket. Although, if you start grabbing your crotch, the deal is off.

 

[Silverunicorn]

 

[EagleTG]

Where'd you get the Michigan hat?

 

[Silverunicorn]

Where'd you get the Michigan hat?

From your mom's night stand, but that's not relevant to the thread

Chris

 

[ifkz]

Err...back on topic, does anyone know a cheap source for 2MBit EPROMS (256K in computer size) part number 27c020? Bob sells them for $5, but then I need 17 of them.

 

[EagleTG]

Err...back on topic, does anyone know a cheap source for 2MBit EPROMS (256K in computer size) part number 27c020? Bob sells them for $5, but then I need 17 of them.

Check with PacManDotCom.com (Riptor). I snagged a few from him a while back.

Also check eBay... Some seriously good deals up there from time to time.

Let me know if you need any info from my semi-working board, I'd be glad to document whatever I can for you. I do have a ROM reader/burner in case you need any of the images, but unfortunately I do not have a PIC chip reader/burner (and I've heard some PIC chips are fused so you can't read them back, I'm sure there are hacks).

Edit: Bah, he's $4.50 a pop. Not much better. ArcadeComponents.com lists them at $2.79 each. That's channelmaniac's website, while I've never ordered from him, I've heard good things... He always is very helpful on the group here.

 

[modessitt]

Btw - I gave him this board, along with a bunch of others. Got them in a bulk deal from a guy who used to strip boards of all socketed chips for reuse or selling...

 

[Womble]

Most likely this was someones scrap board and it has a fault, common ones on Sys18s are bad sprite SRAMs. Quite easy to fix, but repopulating a stripped board will be a pain, it is possible to brute force the PALs if you have them which will then give you the data to burn into new ones, but I dont think anyone has done this with the Moonwalker ones, check the MAME set tho, they are slowly adding in the PAL files.

 

[ifkz]

Okay, so the PALs are like little EPROMS? If that is true and they are game specific, my only hope is to find a non working Moonwalker in the hopes of making one good set out of two.

 

[Womble]

PAL and GALs are programmable logic chips, they don't contain data as such but their configuration is controlled by the data they are programmed with. They basically contain hundreds of logic gates that are all connected together, the data written to them is a fuse map that disconnects the un-required connections leaving a lump of logic that is used to replace dozens of TTL chips on a board. They have a security fuse which when set to open makes the chip unreadable, if you attempt to read the configuration data out you just get gibberish, but the chip can be reset to blank and used again.

There are now methods to analyse one and derive mathmatically what the contents must be but it has only been feasible fairly recently so not many have had it done.

Wish I had one of the devices that can do this as I have a working Moonwalker board.

 

[EagleTG]

This guy has some PAL chips available.

http://retroclinic.com/leopardcats/segalogic.htm

 

[ifkz]

Well, close to $10 each chip isn't affordable, especially since I need five or more. I also can't find an 8Mhz Z80 that the board needs (my spares are all 4Mhz).

At this point, I'll just be on the hunt for a trashed but complete set. I don't know if it is the general state of arcade boards nowadays, but I've seen a lot of older stuff in pretty poor condition. Things like ripped off caps, scratches everywhere, corroded traces, broken corners, PCBs broken in half. I'm sure somewhere in this, someone will have a busted up but complete MJ board looking for a new home.

Yesterday I found a Bloxeed board, but a picture showed it was based on the Genesis arcade hardware instead of the system 18 board I would need. I figure Bloxeed is the cheapest system18 board out there and would make a good harvesting candidate.

After 22 years, my MJ board has made it through in overall very good shape, so I feel pretty lucky. I've repaired much worse.

I went ahead made a WTB post:
http://forums.arcade-museum.com/showthread.php?t=189118

 

[EagleTG]

Well, close to $10 each chip isn't affordable, especially since I need five or more.

Agreed. I happened to stumble on them on his site, was there for a different reason. Thought of this thread.